This invention is directed to making structures of carbon or a carbonaceous material, and more particularly to the preparation of thin-walled and/or porous structures such as honeycombs or ribbons by die-extrusion or other forming processes using carbon pre-cursors as functional ingredients in the formable mixture.
Activated carbon and graphite honeycomb structures are well known in the art. Such structures have been used as supports for catalysts having high surface areas, adsorbent surfaces, filters, etc. For example, Hucke, U.S. Pat. No. 3,859,421, discloses methods of producing carbonaceous bodies by casting a mixture containing carbon-yielding binders such as furfuryl alcohol and furfuryl alcohol resins, polymerizing the alcohol by exposure to mineral acids or organic acids, consolidating the mixture by removal of liquids, and pyrolyzing at temperatures of 250.degree. C. to 2400.degree. C. to generate carbon.
Sugino, U.S. Pat. No. 4,399,052, discloses the extrusion of a mixture containing a thermosetting organic resin into a honeycomb structure which is then dried to eliminate hydrocarbons and effect carbonization, followed by heating to 600.degree.-1000.degree. C. in an oxidizing atmosphere to form an activated carbonaceous honeycomb body.
Although the above-described references, as well as other methods known in the art, provide strong and functional activated carbon structures which perform well in their variously known uses, the methods heretofore used were not altogether efficient. In some, the extrusion or casting into the original shape is required to be performed at an elevated temperature. In others, the solvent originally used to plasticize the mixture to be extruded or casted required removal, a process which can result in unwanted void space, further requiring consolidation or densification to be performed prior to carbon activation.